New Delhi, Feb. 3 -- Cancer is the leading cause of death worldwide, responsible for nearly 10 million deaths in 2020, or about one in six deaths, according to the World Health Organization. It is an umbrella term for a broad range of diseases that can affect any part of the body, often referred to as malignant tumors or neoplasms. It develops when changes in cells lead to their uncontrolled growth and division, which can weaken the immune system and disrupt normal functions of the body. The most common types of cancer include breast, lung, colon, rectum, and prostate. While some types cause visible tumors, such as breast or lung cancer, others such as leukemia do not. It is a deadly disease that remains undetected until it reaches an adv...